Tracer controlled feed mechanism



Feb. 7, 1939. c. K. SALISBURY TRACER CONTROLLED FEED MECHANISM 6 Sheets-Sheet l Filed Feb. 23, 1937 WVf/WJH M fi MM Feb. 7,1939. 3 5 2,146,157

TRACER CONTROLLED FEED MECHANISM Filed Feb. 25, 1937 6 Sheets-Sheet 2 i l I 36s 64 5a? 34/ 3.51/ 4, J

Feb. 7, 1939. C K, SALISBURY 2,146,157

TRACER CONTROLLED FEED MECHANISM 66 mam w m/ww Feb. 7, 1939. c. K. SALISBURY I 2,146,157

TRACER CONTROLLED FEED MECHANISM Filed Feb. 23, 1957 e Sheets-Sheet 4 Feb. 7, 1939. 'c. K. SALISBURY TRACER CONTROLLED FEED MECHANISM Filed Feb. 23-, 1957 6 Sheets-Sheet 5 E 3 ma Feb. 7, 1939. c. K. SALISBURY 2 nuclei} CONTROLLED FEED MECHANISM Filed Feb. 23, 1937 Q 6 Sheets-Sheet 6 wysyvrm Patented Feb. 7, 1939 UNITED STATES PATENT OFFICE TRACER CONTROLLED FEED MECHANISM Charles K. Salisbury, Waterloo, Iowa Application February 23, 1937, Serial No. 127,098

17 Claims. (01. 8214) 1 My invention relates to tracer controlled feed mechanism and is animprovement on my pending application, Serial No. 101,095, filed Sept. 16, 1936, Compound feed control mechanism.

The objects of my. invention are: to provide greater accuracy of finished parts by eliminating unnecessary reversing of the feed screws from hunting, to reduce the efiect of back-lash on the feeding movements, to provide a single magnetic clutch for the automatic operation of a feed screw in both directions, to provide means to reverse the rotation of said clutch by action of the tracer, to provide means whereby the operation of associated feed screws are dependent on each other to prevent unnecessary reversing of feed direction, to provide a tracer adapted to automatically move on three sides of a rectangle, to provide means cooperating with a pattern to control a driving connection with the cross feed screw independent of the tracer, to simplify boring and turning operations, and to provide means to automatically control the feed of the carriage by means of the splined shaft.

With the above and other objects in view, my invention comprises the herein described tracer controlled feed mechanism and all equivalents.

Figure 1 is a plan view of a lathe equipped with the mechanism herein described.

Figure 2 is an end view of the mechanism shown in Figure 1.

Figure 3 is a broken section taken on line 3-3 of Figure 1, showing the cross feed screw take-up.

Figure 4 is a plan view of the tracer unit with the cover removed.

Figure 5 is a side view of the tracer unit with the cover in position and partially broken away.

' Figure 6 is a sectional view of the tracer unit taken on lines G- -S of Figure 4 with the protective cover removed.

Figure 7 is a sectional view of the tracer unit taken on lines,11 of Figure 4.

Figure 8 is a sectional view of the tracer unit taken on lines 8-8 of Figure 4 but with the protective cover in position.

Figure 9 is a plan view of one of the magnetic clutch and brake units sectioned on lines 9-9 of Figure 10.

Figure 10 is an end view of the mechanism shown in Figure 9.

Figure 11 is a side view of the clutch and brake mechanism shown in Figures 9 and 10.

Figure 12 is an end view of a portion of the outer clutch plate showing a driving projection and with release spring. I 4

Figure 13 is a top view of the mechanism shown in Figure 12.

Figure 14 is an inverted plan view of the motor reversing switches and controlling mechanism.

Figure 15 is an inverted side view of the mechanism shown in Figure 14.

Figure. 16 is a sectional view of the mechanism shown in Figure 14 taken on line Iii-l6 of Figure 14.

Figure 1'7 is a partial sectional view of the latch plate and the speed limit switches taken on line l'l-l1 of Figure 14.

Figure 18 is a plan view showing the cross feed screw release in its hookup position.

Figure 19 is a diagrammatic showing of the electrical connections.

Figure 20 is a partial sectional view of the speed cut-out switch mechanism taken on line 20-20 of Figure 14.

Figure 21 is a diagrammatic showing of tracer operation.

Figure 22 shows setting of tracer unit for faceplate'work.

Figure 23 shows a modification of tool setting and a discontinuous pattern.

Figure 24 is a modification using doubletool setting.

Fig. 25 is a modification showing special tool setting.

Figure 26 is a sectional view of a modified magnetic clutch showing an air gap in the magnetic circuit.

A lathe having a bed 50, Figures 1 and 2; is provided with a rotating spindle 51 adapted to carry a work piece 52.

A carriage 53 slides on the bed and carries a cross slide 54 which is provided with a compound rest 56 on which is secured a cutting tool 55 to operate on the work. 7

Two brackets 58 and 59, Figures 1 and 2, are secured at the rear of the lathe. The bracket 59 being broken away in Figure 2 to prevent obstruction of the view.

These brackets carry a support 60 which is provided with a base surface BI and a vertical wall 62 accurately machined in planes parallel with the lathe center.

A pattern 63 engages the wall 62 for cross location and is secured to the support 60 by screws 64.

' readily to reduction of the magnetizing current,- a slight air-gap II5 may be maintained in thein Figures 1 and 2. Thecross slide is moved 9| and the/disc as shown in the modimation in either direction by a cross feed screw 68.

I The cross feed screw is rotated in either direction by a single reversible magnetic clutch 19,

Figures 1, 2, 9 and 10. The carriage is moved in either direction by rotation of either the lead screw or the splined shaft operated by a single 7 reversible magneticclutch Ilia f id nti struction and t The magnetic clutch I9 is provided with a bearing shaft 14 seemed in bearings I5 and I6 to a bracket; I1. ,nil'he body is provided with annular grooves 18 and 19m which are placed the magnet windings 8| and 82in series with each other and connected with insulated collector rings 83 and 84 which are contacted by carbonbrushes 85 and ,99 to maintain a circuit through the clutch windings.

-A clutch disc 86 is provided with a shaft 81 secured in bearings 88 and 89 to the bracket 11 with its shaft in line with the shaft I4 to allow the disc to contact with the driving face 9| of the clutch and to rotate therewith when magnetism is applied. 7

An outer clutch ring 92 is carried by the clutch I9 by three driving brackets 93 secured thereto which engage with driving projections 94 on the outer ring as shown in Figures 9, 10, 12 and 13 to give .positive drive of the ring with the clutch but to permit of slight end movement. The clutch disc 86 is placed between the outer ring and the clutch face 9| and free to rotate when the magnetism is released. The disc 86' is very thin and is held between the clutch face and the outer ring very strongly when the clutch is energized. I

Three small leaf s'prings95, Figures 12 and 13, serve to hold the outer ring .92 in a direction away from the .clutch face when the clutch mechanism is released.

The clutch windings 8I and 82 are held in position by non-magnetic plates H2;

The shaft 81 is provided with a brake disc 96 which rotates therewith, Figures 9,- 10 and 11.

to a bracket TI and actuated by a brake spring I98 to force a quick stop of the disc 86 and parts controlled thereby when the clutch circuit is broken.

Whenthe clutch circuit is energized, coils I95 and I96 supported by a plate I94 secured to the bracket 11 and in series with the clutch windings 8| and 82, act to attract an armature I91 01' the brake lever 99 'and .release the brake. The fixed brake member 91 is adjustably secured to the bearing "by means of adjusting screws I98 and I99. Theclutch body 19, the disc 88 and the outer clutch ring .92 should all be of soft steel adapted for quick magnetic changes to increase the speed of clutch action.

The clutch and the brake discs as well as all parts carried by the shaft'll are made as light as'possible to permit of high rotative speed and quick stopping.

A condenser I I3 is placed across the clutch and brake coil leads to increase the speedl jof de-' magnetizing. 7

As a closed magnetic circuit does not respon'd special clutch body 12 between the, clutch face I34 supported on the lathe carriage by clips I85,

' in a hole I'II bored in the secondary lever (Flg-.

shown in Figure 26. v 7

I, The bracket 11 is solidly bolted to the rear of the carriage 58 and moves therewith. On its lower surface is secured;an 'electric'motor II6 provided with a gear wheel'i I8 meshing with an idle gear wheel II9 supported by'the bracket.

, The idle wheel meshes with a gear wheel I2I secured to the outer end of the clutch shaft I4 to rotate the clutch body I9 in thedirection determined by the rotation of the motor.

The clutch shaft 81 carries a small pinion I22 and a larger pinion I23 rotating therewith. I

A shaft I25, Figures 1 and 2, having bearings I26 supported by the bracket 11, carries a gear set consisting of a gear I2I which-may mesh with the pinion I22 and a gear I28 which may mesh with the pinion I23 by sliding on a spline Any other gear change mechanism may be substituted. y

The shaft I carries a gear I8I adapted to mesh with a gear I32 carried at the rear end of the cross feed screw. By pushing a control rod Figures 1 and 2, a lever I36 connected thereto by a link I38 and pivoted to the bracket at I88, Figure 18, is swung to the latched position shown in Figure 18. The gear I3I is thus moved on its driving spline I4I against a spring I42 by means. of a forked collar I43 pivoted at I45 to the lever I36 to disconnect the gear I3I from its drive of the cross feed screw gear I32. The gears are held out of mesh by aprojection I" on the lower arm I49 on the lever I36 engaging with a projection I48 on an armature lever I5I. This lever is pivoted at I52 to a support I58 secured to the bracket 'II andis retained in latching position by a spring I54. v

A magnet I56 serves to unlatch the lever I86 to force driving engagement of the gears.

To permit of greater ease of engagement of the gears I3I and I32, the 6 38 8 8 ends of the teeth in both gears are out man angle as shown at I51 in Figure 18. This permits 0! positive engagement although the cross slide is being rapidly moved by the operator.

- A tracer, Figures 1 and 2, and detailed in Figures 4, 5, 6, 7 and 8, consists of a base I6I, sIde= walls I62, 9. top plate I63 and a removable protective cover I64.'

A primary lever I66 is secured by pivotpoints I6'I between the top plate I68 and the base I6I' for movement in a single plane. A secondary 5 lever III .is secured to side projections I18 of the primary lever by povot points "4 to also swing in a single plane. A removabletraeer' point I15, provided with a stem "6 which is inserted ure 5) is clamped in position by a taper threaded nut I'I8.

' The center of the tracer point I15 is placed at an angle of about 45 degrees. relative tothe pivot point of the primary lever I66 when moving in thedirection of the one-way feed of the tracer indicated by an arrow I'I8 in figure 4. g This angle is indicated at I" in Figure 4. It is also'placed at an angle relative to the pivot point of the primary to the secondary lever as indi.

' cated at I83 of Figure 4.

40 when it is energized and permit the spring I42 2 otherasshowninFiguresiandi Theyareli provided with contact points I88 normally in contactto carry the line current for operation of the clutches 19 and 1911. These contacts open upon excessive deflection of the tracer point and stop the feed in all directions.

The secondary lever I1I carries a contact arm I89 which .is insulated therefrom and carries three'electrically connected points I9I, I92 and I93. It also carries a plate I95 secured thereto but insulated therefrom by an insulating plate I99, as shown in Figures 4 and 6. This plate has three connected contact points I96, I91 and I98.

A spring 299, Figures 4, 7 and 8, tends to independently hold both primary andsecpndary levers and the parts fixed thereto in their full line positions shown in Figure 4. An insulated screw 29I limits the movement of the secondary lever and the arm I89 in the opposite direction by its point contacting with the lever I89.

A yoke 293, Figures 4 and 5, is secured to but insulated from the end of the safety spring lever I84 and acts to limit the movement of the contact arm I89 away from it but permits of free movement of the contact arm in the opposite direction. An insulated set screw 295 limits the movement of the lever I86 due to action of the spring 299.

The contact points I 9I I92, and I93 carried by the contact lever I89 make electrical contact with contact levers 291, 298 and. 299 in the order given, while the contact points I96, I91 and I98 contact with contact levers 2II, 2I2 and 2I3 in the order named. r

The contact levers are all alike and each is pivotedat a point 2I5 to their base plate 2I6 which is insulated from the tracer base I6l but secured thereto.

A spring 2I1 permits flexible contact movement of the contact lever which movement is limited by an adjustable stop screw 2I9.

The tracer carries the electric control for the clutch' gear magnet coil I56. It consists of a contact lever stem 22I with itsdisc 222 which is seated in a recess in a bracket 223 secured to the side wall I62 of the tracer. A lever 224 swings on a pin 225 secured to the tracer side wall and has one end in contact with the disc 222. A spring 221 serves to maintain pressure against the disc to force the stem 22I to an upright position but deflectable in all directions. When so deflected an insulated contact point 228, Figures 4, and 8 is forced against a contact point 229 of a lever 231 to close the circuit through the magnet coil I56. The lever 23I also swings on the pin 225 and is held against a stop 232 by means of a spring 234 to permit of excess deflectibn of the stem 22I.

The tracer also carries a swinging contact lever 236 adapted to swing with a bearing pin 231 secured in bearings in the base I6I and the top plate I63. The lever 236 carries an insulated point 238 which is normally held by a spring 239 in contact with an' insulated contact point-24l carried by the side wall.

The contact lever 236 cuts out the tracer contacts I96, I91 and I98when using discontinuous patterns.

A plate 243 is secured to the'base I6I of the tracer by means of rivets 244 and serves as a cover to an insulating plate 245 which acts as a bottom insulating support for four binding nuts 246, 241, 248 and 249 insulated from the base I6I.

power circuit while the nuts 248 and 249 connect with the points 238 and 24I for power operation of the coil I56.

The plate 245 also carries five contact springs 25l, 252, 253, 254 and 255 which are all insulated from the base and serve to complete the battery circuits controlled by the tracer.

A rigid arm 251, Figures 1 and 2, is adjustably secured to the cross slide of the lathe by bolts 259 and 26I. At therear end of this arm an insulating circular base plate 263 is secured by rivets 264 and carries three sets of contact points I, 2, 3, 4 and 5, Figures 4,5, 7 and 8, adapted to make contact with the clutch and motor controls and the tracer when the tracer is set in any one of the three operating positions.

A bolt 265 secured to the plate 243, Figures 5 and 7, directly below the center of the tracer point I15 and extending through the center of the circular base plate 263 and end of the arm 251, serves as a pivot on which the tracer is rotated for its various settings. A Winged nut 266 serves to secure the tracer in the desired position.

The motor II6 fordriving the cross feed screw magnetic clutch 19 is identical in its construction and its control with a motor II6a used in driving the magnetic clutch 19a and is here shown as an alternating current motor provided with starting coils 219, Figure 19, for controlling the direction of rotation of the motor and its associated clutch. v

The-motor is provided with an extended bearing shaft 21I which carries a brake disc 212 and a shifting screw 213 which rotate therewith as shown in detail in the inverted Figures 14, 15 and 16.

A secondary shifter and brake plate 214 of nonmagnetic metal and carrying brake coils 215 and 216 is also supported by a bearing 211 on the motor shaft 21! between the brake disc and the shifting screw and is held in neutral position by two springs 218 fixed thereto and having their opposite end secured to a fixed plate 219. Stops 28I and 282, fixed to the lower side of the bracket 11 and provided with cushions 289, limit the deflection from neutral in either direction and serve to prevent undue rotation when serving as a brake.v

A shifter arm 285, Figures 14, 15 and 16 is pivoted to one end of an armature lever 281 which is supported by a bearing column 288 secured to the bracket 11.

The armature lever 281 is held against a stop 29I by a spring 292 to hold a contact end 293 ofthe shifter arm 285 out of contact with the shifter screw when inoperative. A lever 298, Figures 14, 15 and 16 is pivoted at 296 to acolumn 291 secured to the bracket 11. The lever is provided with shifting projections 39I and 302 against which the shifter arm contacts during shifting operations.

Light tension springs 396, having one end attached to a pin 398 on the arm 285 and the other end secured to projections 3I I of the lever 298 serve to hold the arm in midshifted position when its point 293 is disengaged from the shifting screw 213. The shifting screw 213 and associated parts act as a time-delay mechanism.

A slot on the lever 298 engages with a pin 3I1 secured in an arm 3I8 of a switch lever 3| 9 which is pivoted to a bracket 32I secured to an insulating side plate 322. A stop plate 329 limits the movement of the levers 298 and 3I9 in either direction.

A primary switch composed of blades 324 and 325, insulated from each other but held together by an insulating block 326, Figures 14, 15 and 19, are pivoted to brackets 321 and 328 which are insulated from each other by the side plate 322 on which they are secured. The brackets 321 and 328 as well as the brackets 363 and 364 are positioned relative to their connected parts as shown in the Figure 19. These switch blades are thrown by a spring 33! secured one end to the block 326 and at the other end to an arm 332 of the switch lever 3I9 and are adapted to swing freely between the switch blades.

The brake plate 214 is provided with an arm having its endv bent at right angles to form an operating point 335 as shown in Figures 14, 15, 16\ and 1'7. This point engages with a pin 336 secured to a-latch plate 331 during the shifting of the secondary switch in either direction. The 20 latch plate is pivoted at 338 to one end of a lever 34! and is provided with two pins 342 and 343 which engage with a plate 344 secured to the bracket 11. A light spring 346 is secured at one end to a pin 341 of the lever 34! and at its other 'end to an arm 348 of the latch plate to bring it to its operating position after deflection.

The lever 34! ispivoted at 35! to the bracket 11 and at its opposite end is hinged to a connecting link 352 which is hinged to an arm 354 which is of the same construction as the primary switch lever 3!9, previously described.

The switch lever 356 is pivoted to a bracket 368 secured to the side plate 322.

The secondary switch is composed of two short blades 368 and 36!, Figure 19, pivoted to brackets 362 and 363, Figures 14, 15 and 19, which are insulated from each other by the side plate 322 on which they are mounted. The blade 368 has an 40 extended end 364 secured thereto but insulated therefrom by an insulating block 365, while the .tblade 36! carries an extension 366 also insulated from it by the block 365. This divides the secondary switch into four separate parts, insulated from each other but moving to ether.

The secondary switch is thrown by a spring 361 secured to the block 365 and to the switch lever 356 in the same manner as described for the primary switch.

The side plate 322 carries a series of spring contacts 368 for the control of the various circuits when the motor H6 is operating in the direction of an arrow 424, Figure 16. A second insulating side plate 312' carries the contact springs 313 for the control of the various circuits when the motor is rotating in the oppositedirection.

A motor bushing 382,. Figures 15 and.- 28, is

reduced in diameter at its outer end to form a stationary bearing support for a friction flanged sleeve 383 on which it may freely rotate. A second friction disc 381 is f orced onto the sleeve with a'comparatively thin friction plate 388 carried on the sleeve between them. This plate 388 is warped to frictionally bind it between the plates and tends to rotate with it to the extent permitted by a pin 384 engaging in a slot in a rocker lever 39! which is pivoted to brackets 392 secured to an insulating base 393. The rocker-lever, is provided withal'ateral arm 394 on either side of its pivot point which may engage with the free end of contact springs 395 and 396 secured at their outer end to the base 393. The spring 395 carries a contact point adapted to contact with a point carried on a contact plate 331, Figure 20,

of the secondary switch lever 356, Figure l5,

"while the contact spring 396 likewise contacts with a contact plate 398.

A spring 399 serves to maintain the plate 388 -and the rocker lever in neutral position.

The sleeve 383 is provided with a driving projection 48!, Figures 16 and 20, against which a point 483 of either lever 485 or 486 may be moved by a spring 481 when the rotative speed of the motor has sufllciently dropped. These levers are pivoted at 488 to the rear face of the brake disc 212 and are limited by pins 4!! against excessive movement.

. The magnetic clutches 18a and 18 are driven by their reversable motors !!6a and !!6 which operate on volt circuits.

An 8 to 10 volt battery 445 furnishes the current for the operation of the coils 426, 43! and 42 !a controlled by the tracer.

The carriage is driven by identical gear as used' for operation .of the cross slide. A gear 431 on,

the shaft a may slide into driving mesh with a gear 438 on an extension of the splined shaft 66 or it may slide into mesh with a gear 448 on the lead screw 65.

The usual manual controls 441 and 448 movethe carriage and cross slide, while the usual split nut 449 operates the lead screw and a nut 45! controls the carriage movement by operating the regular friction clutch to connect the splined shaft to the transmission gearing in the carriage apron.

Operation in longitudinal turning and boring:

The tracer base 6! is set in the position shown in Figures 1, 2, 23, 24 and 25. The carriage is moved in the direction of the arrow 38, Figure l, by one-way control of the clutch 18a. The cross slide is operated in either direction by the clutch 18. The carriage is preferably driven by the splined shaft which is released at the nut 45! and the gear !3! is released by the control rod !34.

The contact lever 22! carried by the tracer, is.

moved against the edge of support 68 at its starting point 444, Figure l, by the manual controls.

.This energizes the coil !56 to instantly connect the reversed to move the tracer point !15 toward the pattern 63. The tracer point is very close to the pattern but still out of contact and the contact arm !89 is held in the full line position shown in Figure-1 by the spring 288. In this position, the plate !95 on the arm contacts with the contact lever 2!3 and the line circuit through the clutch 18a is broken and the carriage remains stationary. (Contact is also made with the lever 2!2 which also controls the clutch 18a through the coil 42 !a as before but it is now disconnected and its action will be described later.)

The plate !95 of the arm !89 also contacts with the nut the contact lever 2!! which is now in circuit with the shifter coil .426. This operates to move the or the point 233 throws the primary switch to the position shown in Figures 14 and 15. (Contact of the point 293 with the shifter screw may be only momentary and will be described later.)

The connections are now as shown in the diagrammatic Figure 19, with the connection from the motor winding 428 and the starting winding 2m to the linebroken and the brake coil 216 connected.

When the brake coil 216 is energized; the ends of its core 336, which also extends through the coil 215, are held very strongly to the brake disc 212 and the brake plate is rotated against the pressure of the springs 218 until contact of the point 335 of the brake plate with the stop 28L The motor speed, due to inertia, is quickly reduced to near the stopping point and the point 403 of the centrifugal lever 406 engages with the projection 435 of the flanged sleeve 383 to frictionally move the friction plate 388 and the rocker lever 3M sidewise as shown by dot and dash lines of Figure 20 but in the opposite direction to that shown as the motor is rotating in the opposite direction. The contact between the spring 395 and the contact plate 391, in series with the coil 216, is thus broken and the brake released. The springs 218 then act to bring the brake plate to its neutral position as shown in Figure 16 and throw the secondary switch by moving the latch plate and connected parts by contact of the point 335 and the pin 336. The switch then takes the position shown in Figures 14 and 15, the circuit through the brake coil 218 is opened, the motor winding 428 is connected to theline as is the starting winding 210 with reversed connections. At the same time, the shifter coil 426 and the operating coil are reversed in their connection with the contact levers 207 and 2H and the contact levers 2 I 2 and 209 are shifted into control of the coil 42in: operating the clutch ifia instead of the former contacts 2 I3 and 293.

As the tracer arm N9 is maintained at its previous position, contact of the plate Hi5 and the contact lever 2H acts to energize the clutch Id through its coil 33i and the tracer point is moved into contact with'the pattern. The movement is continued until the arm E89 breaks the contact between the plate i355 and the contact lever 2i i and the arm M9 is brought to about the position shown by dot and dash lines of Figure 4 and the cross feed stopped. The primary lever of the tracer is not deflected by this contact but maintains its full line position or as shown in the position 552 in the diagrammatic Figure 21.

In the mean whiie. the contact between the plate I95 and the contact lever 2I2 has been broken and the carriage is moving in the direction of the arrow 38 of Figure 1, to bring the tracer point into contact with the point 446. Figure 1, at the center line 453 of the pattern. Continued movement then swings both primary and secondary levers of the tracer to the position shown at 454 in Figure 21, due to the angular relation of the tracer point and the pivoted point of the primary lever.

When the tracer arm is swung to this position. contact is first made between the arm I89 and the contact lever 20'? which is now connected to the shifter coil 42%. Continued movement of the carriage still further moves the arm I89 until contact is established with the contact lever 209 and the movement of the carriage stopped.

The motor is now ready for reversal in direction of rotation which is done in the same order as before described with reversed movements of the operating parts."

Before the brake plate 214 can swing in the opposite direction in reversing it is necessary that the latch plate swing back to its operating position as shown in Figure 14 after being deflected to the position shown. in Figure 17. This is done when the point 335 of the brake plate has moved close enough to its stop, on either side, to clear the pin'336.

Upon reversal of the motor, the feed of the cross slide will be in the direction of the arrow 3| of Figure 1 and the carriage will operate to the extent required to maintain tracer contact with the pattern. This will continue until a point 458 on the pattern is reached by the tracer point, when reversing will again take place. The motor is again reversed when a point 453 is reached but will then continue until the operation is completed. The tracer then continues to move along the pattern until a point 466 is reached where no further movement is possible because of one-way operation of the carriage. The feed in one direction. or the other, will still persist until the contacts I88 of Figure 4 are opened by the excess movement of the tracer point and the clutches "I0 and Illa are rendered inoperative.

When the tracer is moving over the edge of the pattern at 451, Figure 1, it is desired that there be no reversal of the motor due to very slight inequalities in the pattern which might cause such action. To prevent reversing, a plate 462, Figures 1, 2, 5 and '7, is secured to the bottom of the pattern 63 in position to contact the lever 236 carried by the tracer, to open the contacts 238 and 24I, Figure 4, and disconnect the plate I95 from the battery circuit. This renders the tracer arm I89 inoperative in the direction controlled by the plate E95 but operative in the opposite direction.

This same action takes place where discontinpatterns are used as in the modification Figure 23.

Many times it is desirable to provide a starting point on a pattern where the lever 22E cannot contact with the edge of the support 60. In such cases a starting plate 563 Figures 5, '7, 22, 23. 24 and 25, is secured to the under side of the nattern to'make contact for energizing the coil The starting plate may be used as a stop at other than the regular starting points if desired.

When a second cut over the surface previously machined is desired, the carriage and cross feeds are released in the manner previously described and. the tracer again manually returned to the starting point M4. The tracer point, I is then to permit of its reduced stem I'IG to contact the pattern as is common in such work. The second cut is then performed as previously described.

The advantage of the cut always being taker in the same direction is that the cutting tool may be formed to much greater advanta e, resulting in both better and faster work. To do this, in previous constructions, required great care to prevent damage to the tracer when manually moving it to the starting point.

In boring the form shown in Figure 25, modifled tool action is used. The special cutting tool 464 is turned upside down and is placed to operate on the Work 465 at the rear of the center line of the lathe as required in lathes which are not adapted for machine operation in the reverse direction. The specially formed tracer point 457 follows the pattern 466 in the manner and in the direction previously described for cylindrical turning.

In boring the core box 469, Figure 23, modified,

tool setting is also used. The lever 22I is manually moved against the starting plate 463 and the special tracer point 413 moves along the face 411 until contact is made with a swinging stop plate 415 which stops the progress until comparative measurements, relative to the work and the cutting tool 412, are made. The stop plate is then swung to its dot and dash position 418 and the tracer progresses along the pattern until reaching the point 418 when the contact lever 236 contacts a lengthened plate 419, which is equivalent in action to the plate 462, previously described. "The bore is then formed cylindrical, without movement of the cross slide, until the tracer point contacts the opposite adjustable end plate 482. The work is, from this point, formed according to the pattern and the tracer is stopped and the circuit of both clutches opened by the angled stop plate 483.

In Figure 24 the inverted boring tool 485, indicated by full line, operates on the work 486 under control of the tracer point 413 moving over that portion of the pattern 481 as indicated at 488. The regular boring tool 489, shown by dot and dash lines, operates under control of the same tracer, shown by dot and dash, when moving over that portion of the pattern indicated at 49I. The

tracer point starts in both cases at its starting point 493 and 494 and moves in the same direction.

The advantage of using this method over the face plate method of machining the same part, as shown in Figure 22, is that square corners may be cut at the points 495. In practically all pattern work, such corners are required. The tool action is also very much better.

A'very material advantage of using the modified tool operations shown in Figures 23, 24 and 25, is that one-way operation of the carriage is required, only, even for complicated work and the templets and tracer are then used as in turning In normal tracer action, where no motor re versal is required, the arm I89 will vibrate be tween the contact levers 2II and 281 connected to the operating coil 43I and the shifter coil 426,

and contact both of them if the contacts be set close and a fast feed be used. The contact point 293 of the shifter arm 285 will then engage the shifter screw 213, but no motor reversal will result as it is again withdrawn before contact with the lever 298 and the point 293 returned to its mid-shifted position by the springs 386.

The vibration of the tracer arm. I89 may also alternately contact the levers 288 and H2 resulting in improper operation of the clutch 1811. To prevent this, the contacts 2I3 and 288 are cross-connected, as are the contacts 2I2 and 289. The tracer arm must move much farther to contact the contacts 2I3 and. 289 than in contacting 2I2 and 288. The switch blade 484 connects the proper set for either direction of rotation so that the arm moves much farther for operative con tact on the shifting side than on the operating side.

For maximum tracer efficiency, the contact levers 281 and 2 should be setto permit the tracer arm I89 to move only slightly from its central un -contacted position to contact either. The contact 2I2 should be set to require the arm to move from its central position, double the distance required to contact the lever 2I I, and also double the distance to contact 288 as required to contact 281. The levers 2l3 and 289 require much greater movement for contact than M2 and 288.

It will again be noted that the clutch 18 is energized only upon contact of the tracer arm with contact lever 2 or 281. The clutch 18a is energized only when there is no contact of the tracer arm with the contact levers 2I2 and 289 or with 288 and 2I3.

The advantage of requiring a. greater period of time after contact before operation, and also a greater movement of-the tracer arm on the side not operating, before contact, is that hunting action of the tracer and the clutches, is eliminated.

The effect of back-lash inthe mechanism between the clutch and its screw is entirely eliminated, also, as the movement is always in the same direction.

In those mechanisms using two tracer con trolled clutches or like mechanism for reverse operation, unrestricted tracer control very much slows up the effective operation if back-lash be present as this must be overcome in both directions by the cross slide upon an overthrow of the tracer arm. The work is thus roughened.

The tracer operates with a setting as shown in Figure 4, moving in the direction of the arrow I19 for one-way control of the clutch 18a and moving in both the same and the opposite clirection of the arrow 491 for control of the clutch 18.

The action of the traceris diagrammatically shown in Figure 21, when operating at right angles on three sides of a rectangle. With the tracer'setting as just described, the tracer arm I89 is moved by contact with the yoke 283, carried by the primary lever, when moving in the direction of the arrow 5M and both primary and secondary levers move together for control op;- eration. When the tracer is moving in the direction of the arrow 582, the tracer arm I89 alone moves for control operation as the primary lever is deflected by the spring 288. When the tracer is moving in the direction of the an row' 583, both tracer arm and primary lever are deflected by the spring until the angled face 584 is reached. The tracer arm I89 alone is then deflected to control the operation of the clutches 18a and 18.

The addition of the second lever to the tracer alone allows it to control when contacting the angled face 584 or other similar contact surfaces.

The clutches 18 and 18a must respond very quickly to the tracer action and must magnetize and do-ma-gnetize very quickly. I

The outer clutch plate 92 much reduces the magnetizing effort required for the same effective drive and the clutch disc 88 is much reduced in weight, allowing higher clutch speed.

By placing the clutch disc brake releasing magnets I and I86 in series with the clutch windings 8| and 82, the brake is applied and released much quicker upon clutch action than when using a previously used magnetic brake which is electrically operated for brake application after the clutch circuit is broken.

The magnet coils I85 and I88 may also be placed in parallel, instead of in serles, with the clutch windings (not shown).

To simplify the wiring diagram, the motor Ilia and its clutch 18a are understood to have a battery and operating coils that duplicate those shown in Figure 19, as well as its own controlling switches.

The contact springs 25I, 252, 253, 254 and 255 on the insulating base plate 245 of the tracer, contact with the contacts I, 2, 3, l and! on the base plate 263 in the order given when the tracer is set for longitudinal turning and boring, as shown in Figures 1, 2, 4, 5, '7, 8, 23, 24 and 25. These contacts connect the tracer elements to the battery circuits as shown in Figure 19.

When the tracer base IGI is-swung to the posi-; tion shown in Figure 22, the machine is properly connected for face-plate work. The one-way feed is in the direction of the arrow of Figure 1 and the carriage feed is in either direction by either the splined shaft 66 or by the lead screw 65.

A second longitudinal boring position of the tracer (not shown but opposite in setting to that shown in Figures 1, 23, 24 and 25) may be used. It requires one-way movement of the carriage opposite to the arrow 30.

Back-lash should be eliminated as much as possible in the cross feed screw, as high tool pressures may cause the comparatively light cross slide to suddenly move to the full extent of the back-lash and cause roughened work. By placing a second nut 501, Figures 1 and 3, on the screw in addition to its regular nut 508 which is secured to the slide 54 by a screw 509, and adjustably securing this second nut by clamping screw l aftver adjustment of the set screw 5l2 has moved the tracer action, may be used independently or together in other mechanism than herein shown and I do not wish to be so limited. I claim the ,above described invention broadly and all equivalents.

I claim:

1. In combination, apattern, a tracer adapted to traverse said pattern, means controlled by said tracer for relatively feeding said'tracer in either direction at an angle to said traverse of tracer and pattern, a projection carried by said pattern, and a contact piece moving with said tracer adapted to contact with said projection and prevent the feeding control operating in one direction but permitting it to operate in the other.

2. In a lathe, the combination of a cross slide,

a screw for moving said cross slide in either direction, a tracer carried by saidslide, means under control of the tracer to operate said screw, a fixed pattern adapted to operate said tracer when in contact therewith, means to disconnect the tracer controlled means from the screw, a contact moving with said tracer and adapted to contact a pro- .iection fixed relative to said pattern, and means to re-establish operation of. the screw by the tracer controlled means when the tracer has been manually moved close to the pattern to bring the contact carried with the tracer into contact with said projection but before the tracer has contacted the pattern.

3. In a mechanism of the character described, the combination with a slide operated by power in one direction only and a second slide operated at an angle relative to the first slide by power in both directions, of a tracer comprising a lever pivoted to its support for movement in a single plane, a second lever pivoted tothe first lever and mov able in a single plane, a pattern engaging tracer point on said second lever, contacts in position to be closed by contact upon movementof the tracer point to stop the movement of the first slide, and contacts in position to be closed by contact when the tracer point is moved to operate the which excess movement of the tracer point opens an electric circuit of the power means operating both slides to render them inoperative.

5. In a mechanism of the character described, the combination of a slide mounted for feeding movement, a clutch member operatively connected to move said slide and provided with a thin clutch disc, a power rotated clutch member provided with a driving surface moving adjacent to a face of the clutch disc, a ring disc carried byand rotating with the power clutch member adjacent to a' face of the clutch disc opposite to its first said face, and an electric magnetizing element cooperating with said power clutch member adapted when energized to magnetically bind it with the clutch disc and ring disc to move said slide.

6. In a lathe, the combination of a carriage operated by a splined shaft, a cross slide mounted on said carriage and movable by a screw, a tracer cooperating with a pattern to control the movements of said carriage and cross slide, means to release the carriage from its drive by the splined shaft, means to release the screw of cross slide from control by said tracer, and means whereby control of said screw by said tracer is automatically re-established before contact of the tracer with the pattern when manually moved toward contact.

7. In a lathe, the combination of a carriage moved by power in a single direction, a cross slide carried by said carriage and movable by power in either direction, a tracer co-operating with a pattern to control the power for movements of said carriage and said cross slide, an inverted cutting tool carried by said cross slide to operate at the rear of the center of 'the lathe to bore work carried thereby, and means to operate said lathe when boring with an inverted tool in the same manner as when turning with a tool as commonly used.

8. In a lathe, the combination of a carriage movable by power, a cross slide on said carriage also movable by power, a tracer cooperating with a pattern to control the power for movements of said carriage and cross slide, a cutting tool adapted to operate on work carried by the lathe over that portion of its surface controlled by the tracer in contact with a portion of said pattern, and a second cutting tool adapted to be inverted and operated back of the lathe center to operate on that surface of the work controlled by the tracer when contacting a second portion of said pattern.

9. In a mechanism controlled by a pattern to produce work, the combination of a member mounted for relative feeding movement, a screw co-operating with said member for direct and reverse feed, a magnetic clutch adapted to drive said screw in either direction and to control the feeding movements of said screw, a motor to drive said clutch, means controlled by the movement of said member to automatically operate said clutch, and means controlled by the movement of said member to automatically reverse the direction of rotation of said motor.

- 10. In a mechanism controlled by a pattern to produce work, the combination of a member co-operating with said member for feeding move-.

ments in either direction, a magnetic clutch for feeding movement, a clutch member compris mounted for relative feeding movement, a screw adapted to drive said screw and to control its feeding movements in either direction, meanscontrolled by said member to automatically control said clutch for the feeding movements, and means controlled by the movement of said member to automatically reverse the of said clutch.

11. In a mechanism controlled by a pattern to produce work, the combination of a member mounted for relative feeding movement, a screw co-operating with said member for feeding movement in either direction, a magnetic clutch adapted to drive said screw and to control its feed- ,ing movements for both directions, means controlled by the movement of said member to automatically operate said clutch for the feeding movements, and means controlled by the move- [ment of said member to automatically reverse the direction of feeding movement of said screw.

.12. In a mechanism controlled by a pattern to produce work, the combination of a member mounted for relative feeding movement, a rotatable shaft co-operating with said member to feed it in either direction, a magnetic clutch adapted to drive said shaft and to control its feeding movements in both directions, means operated by the movement of said member to automatically operate said clutch for the control of the feeding movements, and means operated by the movement of said member to automatically reverse the direction of feeding movements of said shaft.

13. In a mechanism controlled by a pattern to produce work, the combination of a slide mounted ing a thin'disc operatively connected to the slide, a power rotated clutch member provided with a driving surface moving adjacent to a face of the disc, 9, ring member carried and driven by the power clutch member adjacent'to a face of said disc opposite to its-first said face, and an electric .produce work, the combination of a member mounted for feeding movement, a power mech-' anism to move the member toward and from apattern, a tracer carried by the member and contacting with the pattern to control the power mechanism, a time-delay mechanism'interposed between the tracer and the power mechanism to delay the response of power action to tracer control when the tracer is deflected into contact in the direction opponte to the feed direction as determined by the pattern but permit of immediate response in the opposite direction, and

means controlled by the time-delay mechanism to alter its connections to the tracer when the of the pattern.

direction of rotation 14. In a mechan'ism controlled by a pattern to,

direction of feed has been changed. by the form 15. In a mechanism controlled by a pattern to produce work, the combination. of a member mounted for relative feeding movements, 9. power mechanism to move the member toward and from a pattern and also transversely thereof, a mov able tracer carried by the member and contacting with the pattern to control the powermechanism and adapted to close a contact having connection for direct control of the power mechanism to move'the member away from the pattern when the tracer is traversing those portions of the pattern that determine that the feed shall be in-that direction, a second contact directly connected to stop the transverse movement of the member when closed by the tracer deflected in thedirection to close the first said contact, a third contact adapted to be closed by the tracer to move the member toward the pattern, a timedelay mechanism interposed between the third contact and the power mechanism to delay its response to tracer action, a fourth contact adapted to be closed ,by the tracer when defiected to close the third contact and adapted to 25 stop' the transverse movement, means operated by the time-delay mechanism to render the fourth contact inoperative when the feed is from the pattern, and means under control of the mechanism when the direction of feed is changed toward the pattern by change in pattern form.

16. In a mechanism controlledby a pattern to produce work, the combination of a member mounted for feeding movements, a power mechanism tofmove the member toward and from a pattem'and also transversely thereof, a movable tracer carried by the member and contacting with the pattern to control the power mechanism, a contact adapted to be closed by the tracer when deflected by the pattern to move the member away from the pattern,- and a second contact adapted to be closed to stop the transverse movement of the member after the closing of the first contact by increased deflection of the tracer which upon reverse movement acts to open the second contact while the first contact is closed to permit of simultaneous transverse-feed and also awayfrom the pattern.

1'7. In a mechanism controlled .by a pattern to produce work, the combination of a member mounted'for relative feeding movement, a rotatable shaft cooperating with said member for feeding movement in either direction, a .clutch adapted to drive said shaft-and to control its feeding movements for'both directions, means' controlled by the movements o'f-said member to automatically operate said clutch for the feeding movements, and means under control of said member to automatically reverse the direction of feeding movements of said shaft.

' CHARLES K SALISBURY. 

